A voltage-regulating drive circuit for an LED luminaire is disclosed. The drive circuit includes one or several series of LED light engines. A voltage source with a regulator is connected to the series of LED light engines to forward-bias the light engines. The circuit also includes a driver integrated circuit, which may drive the series of LED light engines using, e.g., pulse-width modulation (PWM). The circuit also includes a feedback circuit connected to the cathode end of the series of LED light engines. The feedback circuit receives a remainder voltage and creates a feedback output signal that upregulates or downregulates the regulator of the voltage source to keep a minimum operating voltage on the driver integrated circuit and to compensate for variations in forward voltages among LED light engines in the series.

The invention relates to an isolated primary side switched converter (100), comprising a galvanic isolation stage (105) separating a primary side (101) and a secondary side (103) of the converter (100), a secondary side winding (107) of the isolation stage (105), wherein the secondary side winding (107) is coupled to a primary side winding, and wherein the secondary side winding (107) comprises a center tap, a first terminal (T1), a second terminal (T2) and a third terminal (T3) for connecting an LED load (LED1, LED2) on the secondary side (103) of the converter (100), a rectification circuit (109) on the secondary side (103) of the converter (100), wherein the rectification circuit (109) is configured to set the first terminal (T1) at a first electrical polarity, and to set the second and the third terminal (T2, T3) at a second electrical polarity that is different to the first electrical polarity, wherein the third terminal (T3) is electrically connected to the center tap, and wherein a voltage between the first and the second terminal (T1, T2) is larger than a voltage between the first and the third terminal (T1, T3).

A light source driver for a light source of a luminaire. The disclosure proposes to monitor a parameter, responsive to or a cause of a temperature change in a resistive element to facilitate determination of whether the light source driver is compatible with an AC supply. The resistive element in connected in series between the rectifying arrangement, of the light source driver, and the energy storage capacitor for storing charge that powers the light source.

This application discloses an electronic device (e.g., a camera) that a plurality of light sources and a light source driver. The light sources are configurable to a plurality of light source subsets to illuminate a field of view. At least two of the light source subsets include distinct light source members and are configured to illuminate different regions of the field of view. The light source driver is coupled to the plurality of light sources and configured to drive the plurality of light source subsets. In some embodiments, the electronic device includes or is coupled to a camera module configured to capture visual data of the field of view, and the plurality of light sources is configured to provide illumination for the camera module.

This application discloses an electronic device (e.g., a camera) that a plurality of light sources and a light source driver. The light sources are configurable to a plurality of light source subsets to illuminate a field of view. At least two of the light source subsets include distinct light source members and are configured to illuminate different regions of the field of view. The light source driver is coupled to the plurality of light sources and configured to drive the plurality of light source subsets. In some embodiments, the electronic device includes or is coupled to a camera module configured to capture visual data of the field of view, and the plurality of light sources is configured to provide illumination for the camera module.

A light emitting diode (LED) tube lamp configured to receive an external driving signal includes an LED module for emitting light, the LED module comprising an LED unit comprising an LED; a rectifying circuit for rectifying the external driving signal to produce a rectified signal, the rectifying circuit having a first output terminal and a second output terminal for outputting the rectified signal; a filtering circuit connected to the LED module, and configured to provide a filtered signal for the LED unit; and a protection circuit for providing protection for the LED tube lamp. The protection circuit includes a voltage divider comprising two elements connected in series between the first and second output terminals of the rectifying circuit, for producing a signal at a connection node between the two elements; and a control circuit coupled to the connection node between the two elements, for receiving, and detecting a state of, the signal at the connection node. The control circuit includes or is coupled to a switching circuit coupled to the rectifying circuit, and the switching circuit is configured to be triggered on or off by the detected state, upon the external driving signal being input to the LED tube lamp, to allow discontinuous current to flow through the LED unit.

A flicker-free dimming circuit for non-point light source has a TRIAC module, an input module, a conversion module and an output module. The TRIAC module adjusts the voltage phase of an external power supply for the input module to export an input voltage, and the conversion module in a boost circuit structure is provided with a conversion coil and a converter to receive and raise the voltage value of the input voltage to a voltage value of an operating voltage and then supplies the operating voltage to the output module. The output module adopts a fly-back circuit structure and induces the operating voltage to form a driving voltage in a constant value and then outputs the driving voltage to a lamp with a relatively wide light source area. In this way, the panel lamp can meet high safety standards and enhance its product adaptability and competiveness.

An LED tube lamp includes a tube having two ends, two end caps respectively at the two ends of the tube, a power supply module in one or both of the end caps, an LED light strip in the tube; and LED light sources on the LED light strip. Each of the end caps includes a lateral wall substantially coaxial with the tube and an end wall substantially perpendicular to an axial direction of the lateral wall. An axial direction of one or more openings of each of the end caps is substantially parallel with the axial direction of the lateral wall. The LED light sources are electrically connected to the power supply module via the LED light strip. The power supply module includes a fuse, and the fuse is positioned close to the end wall of the first end cap.

Apparatus and methods for lighting. The apparatus may include an LED light source. The light source may be disposed in housing. The apparatus may include a circuit. The circuit may be configured to cause the LED light source to emit light at: a first intensity; and a second intensity that is different from the first intensity. The apparatus may include a mechanical power state selector. A user may use the power state selector to select between LED light sources that are arranged to illuminate in different directions. The apparatus may include a CCT state selector. A user may use the CCT state selector to select a CCT for one or more LED light sources. The CCT may be produced by combining light from one or more LEDs of different CCTs.

Apparatus and methods for lighting. The apparatus may include an LED light source. The light source may be disposed in housing. The apparatus may include a circuit. The circuit may be configured to cause the LED light source to emit light at: a first intensity; and a second intensity that is different from the first intensity. The apparatus may include a mechanical power state selector. A user may use the power state selector to select between LED light sources that are arranged to illuminate in different directions. The apparatus may include a CCT state selector. A user may use the CCT state selector to select a CCT for one or more LED light sources. The CCT may be produced by combining light from one or more LEDs of different CCTs.